Anger. It’s thundering through the Conservative grassroots. Who do these MPs think they are? What right do they have to ride roughshod over their country, their party and their voters?

Since I set up my Stand Up For Brexit campaign, I have spoken to thousands of Conservative activists. Many were willing to cut the party leadership some slack. They were aggrieved that the 2017 election didn’t go as planned – almost certainly due to a hurriedly-devised manifesto which wasn’t properly road-tested. We were sad to see good, Brexit-supporting MPs like Stewart Jackson and David Nuttall lose their seats. But, ultimately, we believed that Theresa May would stick to her promises – her oft-quoted ‘red lines’ – and deliver Brexit.

How wrong we were. Theresa May’s decision in the last 48 hours to overrule her Cabinet and sub-contract Brexit to Jeremy Corbyn is an abomination. This is the man we have rightly said should be allowed nowhere near power; a Marxist terrorist-sympathiser, who has unleashed a plague of anti-Semitism on the Labour movement, the Jewish community and wider society. In her latest appalling decision (there have been many, but this is by far the worst), Theresa May has legitimised him. She has picked a side and, my goodness, she’s picked the wrong one.

Labour, naturally, will make hay with this. The hard-left views and activity of Jeremy Corbyn, John McDonnell and their top team have always been a problem to them. Voters were naturally suspicious. No matter how incompetent the Conservatives appeared, there was still a nagging doubt; a sense that Labour were not really in a place where they could be trusted with the country. Through the travails of Brexit, this was my party’s strongest card. Well, Theresa May has now taken that card and torn it into bits. I fear we shall rue the day.

For many Conservative activists, this was quite simply the final straw. 70% of the party membership and 70% of Conservative voters support Brexit. It’s very clear from the referendum that leaving the EU meant leaving the Single Market and Customs Union, as promised in the 2017 Conservative manifesto. As I write, Twitter is awash with photos of cut-up membership cards. Wealthier supporters have reduced or stopped their donations. Associations are seeing members down tools; individuals who would previously have jumped at the chance to be candidates are refusing to stand. The voluntary party is in meltdown. Indeed, it’s only residual loyalty to the Conservative brand, and the minority of backbenchers who have tried valiantly to deliver on their promises, which is preventing complete collapse.

Activism, as anyone who has campaigned for a political cause will know, is hard work. Long hours, delivering literature and engaging with people who don’t necessarily wish to be engaged with – all at your own expense. You do it to get people elected who believe in the same cause as you. If that MP – be it Dominic Grieve, Anna Soubry, Heidi Allen or any other – proceeds to reveal that they have no intention of keeping their key promise, it is a huge kick in the teeth. Despite the accusations to the contrary, Brexiteers have been forced to compromise repeatedly. “Plan A+” and “the Malthouse Compromise”, all have fallen on the deaf ears of a Prime Minister who sees Brexit as a bomb to be neutralised and a Parliament in which the majority – despite their protestations about honouring the result – wish to Remain.

Throughout all of this, CCHQ’s behaviour has been dreadful. Tin-eared and dictatorial. For nine months, members have been ignored and gaslighted. Now they’re being asked to row in meekly behind the complete betrayal of our manifesto – and, in this sudden appeal to Corbyn and his anti-Western Marxist agitators, betrayal of our shared conservative values too.

What a sad state of affairs. For the Tories, Brexit presented an historic opportunity to reconnect with the working-class vote which kept Margaret Thatcher in power and prove that we are not a party of the establishment, but a party of everyone. Instead, it finds itself gripped by an existential crisis – and Parliament in a self-indulgent, completely unnecessary deadlock.

Conservative Leavers, like all Leavers, are deeply frustrated and cross. But we must filter this energy into reform; of the party and the system – from the ground, up. Despite everything, our country still needs us. And it still needs Brexit.